Methods of anterior cruciate ligament (ACL) reconstruction (tenodesis) using interference screw fixation are described, for example, in U.S. Pat. Nos. 5,211,647 and 5,320,626. In general, these methods of tenodesis involve drilling a tunnel through the tibia, drilling a closed tunnel (socket) into the femur, inserting a substitute ACL graft into the tunnels, and securing the grafts to the walls of the tibial and femoral tunnels using interference screws or the like. Accurate positioning of the tibial and femoral tunnels is accomplished using a drill guide, examples of which are disclosed in U.S. Pat. Nos. 5,269,786 and 5,350,383, incorporated herein by reference.
One drawback of the described tenodesis methods is that forming the tibial tunnel involves removal of significant amounts of bone material. U.S. Pat. No. 5,603,716 to Morgan et al. discloses a technique for ACL reconstruction that avoids the above-noted problem by forming sockets in both the femur and the tibia using a coring bone harvester. The harvester is impacted into bone to a desired depth so that bone material collects as a bone core within the harvester tube. The bone core is extracted from the bone socket using a simultaneous twisting and pulling motion. Such harvesting of bone cores in the joint is technically difficult.
Accordingly, the need exists for a method of ACL reconstruction that provides tibial socket formation without the need for extracting a bone core to form a bone socket. U.S. Patent Application Publication No. 2004/0199166, entitled ACL RECONSTRUCTION TECHNIQUE USING RETRODRILL (commonly assigned to Arthrex, Inc.) proposes a solution using a rotary drill technique such that the tibial and femoral sockets need not extend completely through the bone. However, in this technique, the cutter used must be removed within the joint cavity and flipped around in order to form the second socket. An improved method of forming these types of retrograde drilled sockets is desired.